A 4–32-GHz Chipset for a Highly Integrated Heterodyne Two-Port Vector Network Analyzer

This work presents a chipset for a highly integrated heterodyne vector network analyzer (VNA) with two ports and a multi-octave bandwidth from 4 to 32 GHz. The chipset is comprised of a stimulus integrated circuit (IC) with two selectable single-ended output channels and a four-channel receiver IC. Both chips contain a frequency synthesizer with an average output power of 2.5 dBm and a single-sideband phase noise between -96.3 and -115.3 dBc/Hz at 1-MHz offset. The synthesizer consists of an array of three voltage-controlled oscillators with tuning ranges between 24.8% and 28.2% and a bandwidth extension stage. Wideband design techniques based on cascaded emitter followers are applied to a variable gain amplifier with a peak gain of 15.1 dB and to a wideband source switch with a minimum isolation of 23.6 dB. Single-ended receiver components such as a wideband low-noise amplifier with an average gain of 10 dB and a micromixer are used to compose the four-channel receiver with an average conversion gain of 14.4 dB. A hybrid microwave integrated circuit was fabricated in order to prove the functionality of a VNA utilizing the proposed chipset and wideband directional couplers. The measured scattering parameters of an arbitrary device-under-test showed an average deviation of 0.18 dB in magnitude and 1.8
^°
in phase from the measurements obtained with a commercial VNA.